For former Massachusetts Gov. Mitt Romney, the GOP presidential campaign is looking like a simple matter of survival.

With a substantial chunk of the Republican Party appearing unenthusiastic about embracing him, Romney now finds himself in the position of having to “hang around” in the GOP race while conservatives flirt with a series of alternatives.

After first getting excited about Minnesota Rep. Michele Bachmann, then Texas Gov. Rick Perry and most recently businessman Herman Cain, conservatives still seem to be looking for someone — anyone — they can embrace as an alternative to Romney.

But so far, none of the alternatives has shown much staying power in the race.

Bachmann looked to be developing as a serious choice, but her numbers crashed when Perry entered the contest. Then Perry looked like the obvious alternative, until he opened his mouth.

Cain’s spike in the polls makes him the latest conservative alternative to Romney, but his tendency to speak first and only then think about what he wants to say isn’t exactly an asset when running for the nation’s top office.

Cain’s ability to be spontaneous is an asset, of course, but he does it too often. It has gotten him into trouble and almost certainly will do so again.

Plenty of Republicans would love to nominate a conservative African-American just to stick it to President Barack Obama and liberals who dismiss the GOP as a bunch of racists (making Cain an executive branch version of Supreme Court Justice Clarence Thomas), but the former pizza company CEO has a long way to go to demonstrate that he has the skills necessary to run the country.

“Cain needs to have a second act, and it isn’t clear he will have one,” said one veteran GOP observer who believes that Cain’s 9-9-9 proposal, while passionately supported by some talk-radio hosts and activists, won’t have broad appeal in the party.

Oddly, Romney probably benefits from the seemingly endless series of televised debates. That’s usually not the case with someone as well-known as Romney, who began the 2010 Republican race as the frontrunner and has remained in the top tier as the other candidates have bounced around from tier to tier.

The former Massachusetts governor has used the debates to repeat conservative themes, and Perry’s record on immigration has given Romney an issue on which he can paint himself to the right of the governor of Texas — a good place to be for a hopeful viewed by many Republicans as relatively moderate.

The more often Republican primary voters see and hear Romney talking about big government, high taxes and immigration, the greater the chance that they may ultimately conclude that the former governor is acceptably conservative.

Many conservatives, of course, will never accept Romney. For them, his sincerity is and will always be in doubt.

But Romney doesn’t need to become the conservatives’ favorite. He merely needs to become acceptable to them, at least as long as they don’t find an alternative about whom they can become excited.

Fundamentally, Romney needs to follow the path of Sen. John McCain in 2008 — at least to the point when the Arizonan wrapped up his party’s nomination in the spring of that year.

McCain was never the darling of conservatives, and they embraced his candidacy only after he selected former Alaska Gov. Sarah Palin for his running mate and the presidential contest was fully engaged, making it a choice between two increasingly ideological parties. Similarly, conservatives would embrace Romney against Obama next year.

That Romney has become the 2012 version of McCain surely is one of the great ironies in the race, considering the animosity that each man felt for the other at the end of the 2008 GOP contest.

Perry still has a window of opportunity to establish himself as the conservative alternative to Romney, but as one Republican strategist told me recently, it is closing rapidly.

“Perry’s attacks on Romney are a huge mistake,” the strategist said. “There is no need to attack a guy stuck at 27 percent in the polls. Perry’s biggest problem is Perry, not Romney. The main thing Perry needs to do is to get people to like him.”

That makes sense to me.

Any true-blue conservative in the GOP race doesn’t need to peel supporters off the former Massachusetts governor. He or she merely needs to become “the” alternative for the three-quarters of Republican primary voters who so far haven’t backed the best-known, most-polished GOP presidential hopeful.

Attacking Romney may make Perry feel good, but it won’t make the Texan appear more likable or presidential.

Few insiders expect Romney to make a major mistake in the next few months. He regards planning and preparation as absolutely crucial, so he rarely improvises. That makes him both the man to beat in the GOP race and also the candidate that many Republican voters can’t, and won’t, get excited about.